Samudrika (Garga) 1.57

1.57

jihvātālulakṣaṇamāhajihvā raktā dīrghālakṣṇā susamā ca bhogināṃ jñeyā
śvetā kṛṣṇā paruṣā nirdravyāṇāṃ tathā tāluḥ

He states the characteristics of the tongue and palate:
A tongue that is red, long, smooth, and very even is to be known as belonging to enjoyers of pleasure;
a white, black, or rough tongue—and likewise palate—belongs to the destitute.